Denition
Intentionally blocking a website to disrupt business and/or communication for its users.
This is typically done by sending more packets to a website than it is capable of handling. This doesn’t
actually shut down the website, but slows it to the point of being virtually unusable for anyone. A
Distributed Denial of Service a#ack expands on this concept by using numerous hosts to send packets.
Example
October 2016 DDOS a#ack on Dyn DNS services
Prevention
In a simple DOS a#ack, prevention is fairly easy. The manager of the website being a#acked can simply
disable requests from the single a#acker. This isn’t e.ective in the case of a DDOS a#ack however. DDOS
a#acks can scale up to use thousands of slave hosts. Sorting hostile requests from legitimate ones is very
difficult. If the manager just disables everyone’s requests, then the end result is the same; no one can
access the website. Not disabling any connections will cause the server to be overwhelmed, rendering it
inaccessible as well.
Talk more about how to stop DDoS a#acks by distributing network resources and disabling things like
Ping or certain ports for various types of a#acks.
